| 摘要 |
PURPOSE:To allow the display unit of a radio receiver to display a reception frequency in tuning operation by driving a timer circuit by an AGC voltage, etc. CONSTITUTION:Counter 22 counts a reception frequency and in the 1st tuning operation, this count value is stored in memory 23. In the 2nd tuning operation, arithmetic circuit 24 makes a comparison between a 1st tuning frequency stored in memory 23 and a frequency of counter 23 in the 2nd tuning operation to detect a tuning direction and tuning speed, thereby leading an output out from an output part. This output operates timer circuit 3 to change display part 5 from time circuit 6 to reception frequency counter 22. Further, D-type FF31 is supplied with signals for AGC, etc., of the receiver, and consequently timer circuit 3 starts operating. |
